Possible Large Fibre Polyneuropathy after CTR surgery
My Carpal Tunnel symptoms started with intense itching of my right forearm in May 2020 and worsened thereafter. Conservative treatments of splinting, pain relief and 2 steroid injections (one under ultrasound) didn’t work so a NCS was done and the Carpal Tunnel surgery took place in November 2020. After the surgery, I didn’t experience the relief I had hoped for. In fact the symptoms only mildly improved on the radial side of the hand but new symptoms developed right after the operation, on the ulnar side causing pain and functional deterioration. Now, I have pain, numbness, tingling and the myriad of other sensations one would expect with nerve issues in all four fingers (thumb feels relatively normal). I have numbness on the ulnar side of the hand which extends up the outer side of my arm to the elbow. The fatty area on the palm side of the hand (hypothenar area) is hard, swollen and sometimes shiny. The hand is in a constant state of spasm. I had a second NCS and the results have been interpreted by the neurologist as follows:
1. Right median-digit II SNAP has normal distal latency and moderately reduced amplitude
2. Right ulnar-digit V SNAP is absent
3. Right radial SNAP has moderately reduced amplitude
4. Right median-APB, ulnar-ADM and ulnar-FDI CMAP’s are normal
The neurologist wants to do more tests to confirm his initial diagnosis is generalised large fibre polyneuropathy. He says that there is significant interval change in the right ulnar sensory response since the previous study of September 2020 when it was normal.
My hand surgeon has discussed these findings with me. I asked him if it is not more likely that these new symptoms are as a result of an event during the carpal tunnel surgery rather than this new found polyneuropathy. I asked would soft tissue damage affecting the Guyons Canal be a possible cause. He said that he wants to see what a more detailed NCS and MRI reveals first. He’s not adverse to a second surgery if that’s what is indicated after the tests.
My question is, are there any other specific questionsI should ask my hand surgeon. To me it seems obvious that the problems I have now are directly related to the surgery. I understand his reluctance at going straight to a second surgery but this poly neuropathy seems like a real curveball.
Thanks in advance for any advice you can provide.
My immediate reaction to that story is to question the original diagnosis of CTS. Do you have the original set of nerve conduction studies for us to look at? A diagnosis of polyneuropathy really requires the examinatioon of more nerves - the other hand and at least one foot. The one thing that does seem to be clearly abnormal in those few results is the u;lnar sensory potential so one has to ask about an ulnar nerve lesion or thoracic outlet syndrome. I'm happy to look at the full NCS results if you have them. JB
Thank you so much for your time. I have forwarded the two Nerve Conduction studies (before and after surgery) to your email address. There is no reading for the radial nerve in the before study, but I can tell you that I had no symptoms of radial nerve neuropathy in the hand prior to surgery. The issue related to the median nerve only. I have no problems (now or before) of any description with my feet or left hand so I’m wondering do I need to see neurologist at all? From time to time, I have a slight numbness in the front right thigh (I’m mentioning this in case it has a bearing on your thought process).
I am going for an MRI next week to scan my right hand. Do you think that will be useful for detecting the problem in the hand? Can you suggest any other diagnostic tests that might be useful.
Thanks again.
I should mention also that I have rheumatoid arthritis.